Compass card



July 6, 1929- J. R. METCALF 1,720,964

COMPAS S CARD Filed Feb. 20, 1924 l 'Anil'l 0 4 "llllm mm lm 'L 2 Patented July 16, 1929. Y i UNITED STATES PATENT OFFICE.

.TOI-IN R. METCALF, F ERIE, PENNSYLVANIA.

COMPASS CARD.

Application filed February 20, 1924. Serial No. 693,996.

This invention is designed to simplify dinal and intercardinal points are the incompass cards so that they may be more verted 221/0 points 59. These are of dia- V easily read. lVith the ordinary compass mond form corresponding to the form or' Course diagram there is the inner compass the 221/0 points on the inner compass card. 60

card corresponding in marking to the ordi- The 11%"` points 6 are in the form of innary compass and surrounded by an outer 'vcrted triangles, the bases of the triangles compass card. In such cards as heretofore extending from the angles lat the sides of Ymade the outer compass card does not correthe diamonds ot the 22%,@ points in the same spgond in form to the inner compass card manner a's on the inner compass card and G5 and consequently errors are very easily in the manner of marking usually found on made in the reading thereof. Compasses except -that they are inverted.

In the carrying out oi" my invention I Between the compass points 'are the haltmake the compass card with the usual point and quarter-point markings 7 and points, many of which are of triangular Y8, these being of less depth than the lll/4Eo 70 form and makethe outer compass card of points and 'corr-espendingy iii-this respect the same form as the inner compass card with the similar half-point and quarterbut with the markings oi the points inpoint markings of the inner compass card. verted. Thus the cardinal and intercardi- Thus the nnirkings on the outer compass nal points are preferably oi the usual tricard correspond exactly to the markings of 75 angular shape and of greater depth than the the inner compass card and thus to the intervening lllLO-points, and the 22%0- usual markings oit the compass except that points have the usual diamond form correthe markings of the outer compass card are sponding to the diamond `form of the inner inverted. compass card. Thus confusion is avoided The outer compass card 9 has the degree 80 in reading the diagram. scale 10 with the points corresponding eX- The invention is illustrated in the accomactly to the scale surrounding the inner panying drawing which shows a plan View compass card except that it is inverted. of the compass course diagram. This is Vhat I claim as new is 2- formed with, an inner compass card l, havl. A compass course comprising an inner S5 3o ing theusual surrounding scale of degrees 2r compass card having compass points com- The inner compass card has the cardinal prising some of triangular shape and a depoints 3, the intercardinal points 4, the gree scale indicated thereon; and an outer 5221/2" points 5, and the lll/O points 6 with compass card surrounding the inner comthe usual halt-point and quarter-point pass card and iixed therewith and having 90 markings 7 and 8 respectively. These folpoints some of triangular shape and a delow exactly the usual compass markings, gree scale radially separated from and corthat is to say, the cardinal points 3 and responding to the inner compass card, the intercardinal points 4, except north, are of triangular points on the outer compass card triangular shape and have the full radial being similar in form to the points on the 95 depth of the point portion of the card. The inner compass card but inverted relatively 221/20 points 5 are of the usual diamond to the points on the inner compass card and form and the lll/LO points 6 are of the usual the degree scales on each card being related triangular shape but of less depth, usually to the points.

about halt the depth of the triangular 2. A compass card comprising an inner 10o shaped cardinal and intercardinal points. compass card having compass points com- The half-point markings are much smaller prising some of triangular shape indicated than the lll/Lo point markings and the thereon; and an outer compass card fixed quarter-point markings smaller than the with and surrounding the inner compass half-point markings in the usual manner. card and having cardinal points, intercar- 105 The outer compass card has the cardinal dinal points, QQl/O'points, and 111/4o points points 3a and the intercardinal points ta. thereon separated radially from and cor- These are large triangles extending the responding to the pointson the inner comfu'll radial depth of the point portion of pass card, said outer compass card compris-- the outer compass card in a manner similar ing some points of triangular shape, said 11o 5 to the same points on the inner compass points being inverted relatively to the corcard. Between these triangular shaped carresponding points on the inner compass card, the Cardinal, intereardinal and 221/2" points being of greater radial depth than the 11%O points, Said cards having degree Scales thereon related to Said points.

3. A compass eard comprising an inner eoinpase card having compass points comprising Sonie of triangular shape indicated thereon with Cardinal pointe or triangular forni, and B21/2O points oit diamond forni; and an outer compass card surrounding; the inner` eoinpase card and liKed therewith having ea rdinal points oi. triangular forni in verted relatively to the cardinal points on the inner Compass card and 221/20 points of diamond forni, said Cards having degree scales thereon related to said points on the respective cards.

4. A compass eardV Comprising an inner een'ipaee card having' complies peinte coni-- arieino' soine of triangular sha )e indicatedV 2D ce thereon, the cardinal and intereardinal points being oi' triangular form and the full radial depth of the point portion of the card, the 2.21/20 points being of diamond 'forni and of l'ull radial depth of the point portion of the card7 and the 11%o points beingof triangular form and of less depth than the cardinal and intereardinal points; and an outer compass card surrounding the inner compass card fixed therewith and having cardinal and intereardinal points of triangular forni and of full radial depth of the point portion of the outer Compass eard, the '2241/0 points odiainond 'form and full radial depth or the point portion of the outer compass card and the 11%o points ot' triangular form and of less radial depth than the point portion oit the outer oo1npass card, the points ot the outer compass Card being spa-eed radially from the points of the inner Compass card and inverted relatively thereto, .Said cards having vdegree Scalea thereon related to said points on the reepeetive cards. l

1n testimony whereof I have hereunto Set my hand. Y

JOHN R.' METCALF. 

